Example 112. floating point math routine using fs – Intel 80C188XL User Manual
Page 301
MATH COPROCESSING
11-16
Example 11-2. Floating Point Math Routine Using FSINCOS
$mod186
$modc187
name example_80C187_proc
;DESCRIPTION:
This code section uses the 80C187 FSINCOS transcendental
;
instruction to convert the locus of a point from polar
;
to Cartesian coordinates.
;
;VARIABLES:
The variables consist of the radius, r, and the angle, theta.
;
Both are expressed as 32-bit reals and 0 <= theta <= pi/4.
;
;RESULTS:
The results of the computation are the coordinates x and y
;
expressed as 32-bit reals.
;
;NOTES:
This routine is coded for Intel ASM86. It is not set up as an
;
HLL-callable routine.
;
;
This code assumes that the 80C187 has already been initialized.
;
assume cs:code, ds:data
data
segment at 0100h
r
dd x.xxxx
;substitute real operand
theta
dd x.xxxx
;substitute real operand
x
dd ?
y
dd ?
data
ends
code
segment at 0080h
convert
proc far
mov
ax, data
mov
ds, ax
fld
r
;load radius
fld
theta
;load angle
fsincos
;st=cos, st(1)=sin
fmul
st, st(2)
;compute x
fstp
x
;store to memory and pop
fmul ;compute
y
fstp
y
;store to memory and pop
convert endp
code
ends
end